90 percent AFUE Gas Condensing Furnace Review

Updated November 30, 2014
90 percent AFUE gas furnace

Also known as condensing furnaces, furnaces with AFUE ratings of 90 percent or greater condense the water vapor in exhaust gases to extract additional heat. Venting is directly through a wall to the outside through a PVC pipe, rather than through the chimney. This efficiency comes at a cost, however. Experts say a condensing furnace may cost about $1,000 more than a furnace with an annual fuel utilization efficiency (AFUE) rating of around 80 percent. Installation costs may be higher as well. However, because a condensing furnace will use less fuel over time, the energy savings may be enough to recoup the extra cost. In addition, a condensing furnace will emit less carbon dioxide, which may be an important factor for those concerned about pollution.

ProsLow long-term energy costs, Low CO2 emissions, You may be able to buy a smaller furnace, May qualify for local tax credits and utility company rebatesConsHigh initial costs, Less cost-effective in mild climate

Keep in mind that regulations that went into effect in May 2013 mandates furnaces with 90 percent AFUE ratings or greater in 30 northern states; the requirement is for an 80 percent rating in the 20 other, milder-climate states. These regulations only apply to non-weatherized furnaces. Beginning Jan. 1, 2015, weatherized furnaces will need to also meet the 90 percent rating standard in 30 northern states, and an 81 percent AFUE rating in 20 milder-weather states. A condensing furnace with an AFUE of 90 percent or more may qualify for a local tax credits or utility rebates, but, as of 2014, they are no longer eligible for federal tax credits. For a complete, state-by-state list of credits and rebates, visit the Database of State Incentives for Renewables & Efficiency (DSIRE) website.

Our Sources

1. EnergySavers.gov

Furnaces and Boilers, U.S. Department of Energy, June 24, 2012

This article compares low-, mid-, and high-efficiency heating systems and offers advice on whether to choose a high-efficiency unit. A table shows the possible cost savings of replacing an older, less efficient furnace. There is also a listing of the 30 Northern states that require an AFUE of 90 percent or greater.

2. ConsumerReports.org

Gas Furnace Buying Advice, Editors of ConsumerReports.org, September 2014

This buying guide examines the types of furnaces available today and discusses how to determine if your furnace needs to be repaired or should be replaced. For replacement furnaces, the cost differences between high-efficiency furnaces and midrange furnaces. Unlike other content on this site, this article is available to nonsubscribers.


ENERGY STAR Most Efficient 2014 - Furnaces, U.S. Department of Energy, Not Dated

These are the most efficient furnaces of 2014 according to the U.S. Department of Energy. All of these models have an AFUE rating of at least 97 percent. Annual operating costs and energy use are also detailed.

4. American Council for an Energy Efficient Economy

Heating, Editors of American Council for an Energy-Efficient Economy, Not Dated

Editors recommend high-efficiency furnaces, even for those living in milder climates. This site has lots of information relating to energy-efficient appliances and calculating your return on investment.

5. TheFamilyHandyman.com

Do I Need a New Furnace?, Editors of The Family Handyman, Not Dated

In this article, editors of The Family Handyman talk to HVAC pros to drill down on a variety of furnace-related topics, such as choosing a furnace and the pros and cons of various furnaces types. They also have tips for choosing a contractor and saving money on the initial purchase.